The invention relates to a flat panel display, and in particular to a backlight module for a flat panel display.
Backlight modules of flat panel displays are conventionally edge or direct types. Because the luminous flux of a small-sized display is lower, edge backlight modules are usually applied. Since large backlight modules require higher luminous flux, direct modules are used to increase light sources. Usually, 20.1 to 46 inch flat panel displays require 12 to 28 cold cathode fluorescent lamps.
However, cold cathode fluorescent lamps decrease luminance thereof over time. Referring to FIG. 1, a direct backlight module 3 comprises a diffuser 31, a frame 32, a reflecting sheet 33, and tubes 34. The frame 32 connects the diffuser 31 and the reflecting sheet 33. The tubes 34 are disposed in the frame 32 and emit light reflected to the diffuser 31 by the reflecting sheet 33. Deterioration of each cold cathode fluorescent lamp, however, is different, causing uneven illumination. If new lamps only replace darker lamps, the new lamps are still brighter than other lamps not yet replaced, such that replacement all lamps simultaneously is required. Lifespan and convenient repair of displays are important market factors.